Course is the direction relative to north that the target is going, if the target is heading 090 TRUE then he's going east. His course would still be east if you were heading north south east or west, his course would be the same if you didn't exist. Bearing is the direction TO the target, there are two of those;
https://en.wikipedia.org/wiki/Bearing_(navigation)
European navies have a simpler method, zero to 180 degrees port or starboard from your own ship's bow. A target 45 degrees left of the bow would be RED 45, 135 degrees right of the bow would be GREEN 135. US Navy would say bearing 315 for 45 degrees left of the bow, the RELATIVE bearing is assumed unless unless otherwise specified as TRUE or MAGNETIC.
When you get a target report, location and heading tell you where it is and which way it's going, there would be no information on the relative bearing since the guy sending the radio message has no idea which way your ship is heading.
When you find his position on a map, draw a line from that position in the direction he's going, then plot an intercept course for yourself - don't head for where he is now, head for where he will be 12 hours or 24 hours from now (how far that is depends on his speed) and wait for him there.